Prenatal Diagnosis and Ultrasound

Screening for Down's syndrome (cont.)
The woman who has had four miscarriages and is 41 years of age will be much more reluctant to consider an invasive procedure, when compared to the mother who already has an affected child.

Diagnosis of abnormalities
With the introduction of real time ultrasound it is possible to diagnose many physical abnormalities that occasionally affect a fetus. Some of these problems are not serious, some will require surgery or medical treatment, which can be planned, and a small number will be more serious, leading to major handicap or death. We traditionally rely on ultrasound at around twenty weeks to check for abnormalities, but improved technology means that we can now diagnose many problems as early as the 12 week scam (see Ultrasound)

Diagnosis of genetic disorders
It is difficult to check for gene defects unless you know precisely where the gene is. Although we have mapped the human genome, we still do not know the location of many of the more rare genetic disorders, which often happen as one off problems in a pregnancy.

More common geneteic disorders, where there is a family history and precise knowledge of the gene site, can be tested for. (Continued next page)